The present invention relates to a plush-knitting sinker for a circular knitting machine, a holding-down sinker and knock-over sinker for a circular knitting machine, as well as a circular knitting machine in accordance with the introductory clause of claim 3. Moreover, the present invention relates to a knit plush fabric including a base knit fabric formed by a base yarn and piles projecting from the base knit fabric.
Knit fabrics are known to be provided with yarn loops projecting on one or both sides from the base fabric. Such knit fabric is referred to as plush. When the loops projecting from the base fabric are left as closed loops a so-called pile surface, also referred to as xe2x80x9cxc3xa9pinglxc3xa9exe2x80x9d surface is created. It is likewise possible to cut of the turns of the loops so that separate yarns are left that project from the base fabric. In such a case, a so-called pile fabric or velour is obtained.
The projection of plush knit fabric may be realized in particular in a circular knitting machine. Circular knitting machines of the known type comprise the following elements:
(a) a row of needles in circular arrangement for forming the stitches and loops, whose rising and lowering movement is controlled by a lifting cam or needle lock along a needle cam;
(b) a holding-down and knock-over sinker (hereinafter briefly referred to as down sinker) as well as a piling sinker, with the down sinker and the piling sinker being disposed in parallel with each other between two respective needles and being able to carry out a reciprocating movement horizontal relative to the needles, which movement is controlled by a sinker lock along a first sinker cam for the holding-down and knock-over sinker and another sinker cam for the piling sinker;
(c) control elements for needle selection in correspondence with the pattern, with the selection of a needle resulting in the fact that the needle follows the needle cam present at its instantaneous location whilst a non-selected needle remains in a home position (circular movement position);
(d) yarn guiding means for feeding a base yarn as well as at least two loop or pile yarns for producing the pile loops.
It is possible in such a circular knitting machine it is possible to predetermine, for a particular stitch of the produced knitting, via the control elements whether a pile loop is to be formed or not with the first and/or the second pile yarn for this stitch. The production of a pile loop takes place only when the needle associated with the particular stitch is selected by the control elements when it passes along the respective stitch at the respective loop yarn. The use of different yarns for the loop yarns permits the production of pile loops of different colors or of different yarn qualities.
The height of the pile loops projecting from the base fabric is controlled by means of the piling sinker in the circular knitting machine, above whose upper edge the loop yarn is retained while the needle draws down a loop out of the yarn (so-called pre-couliering).
Further details of the structure and of the mode of operation of circular knitting machines may be read, for example, in the book xe2x80x9cRundstrickenxe2x80x94Theorie und Praxis der Maschentechnikxe2x80x9d [Circular knittingxe2x80x94theory and practice of stitch techniques] by Iyer, Mammel, Schaechxe2x80x94Bamberg: Meisenbach (1991.
The present invention has been based on the problem of providing a knit plush fabric and a circular knitting machine suitable for producing same, with the knitting being intended to present a novel structure of good visual appearance.
This problem is solved by a piling sinker for a circular knitting machine, which is characterized by the feature that it comprises at least two planes for couliering a pile loop. As has been explained in the foregoing, the height level of the upper edge of a piling sinker determines the length of a pile loop. Conventional piling sinkers are provided with a single upper edge only for couliering the pile loop yarn so that the loop length (also referred to as pile height) is the same for all plush pile loops. In the inventive piling sinker, by contrast, two planes are formed on the piling sinker for couliering a pile loop yarn, which are located at different levels and result accordingly in different pile heights of the pile loop yarns couliered above the respective plane. Which plane is used for couliering a pile loop yarn may be determined by the extent of the radial advance of the piling sinker. The plane used for couliering must be advanced here up to the needle circle.
Due to the use of the inventive piling sinker, it is possible to produce pile loops of different pile heights. The use of the piling sinker in a circular knitting machine suitable to operate with at least two pile loop yarns hence permits the production of pile loops of different heights from respective different yarn materials. The production of such a knit fabric has so far neither been known nor was it possible.
The present invention moreover relates to a holding-down and knock-over sinker (hereinafter briefly referred to as down sinker) for a circular knitting machine, which is characterized by the feature that it comprises at least two planes for tensioning a pile loop yarn. Such a down sinker may be used in a circular knitting machine of the aforementioned type for tensioning pile loop yarns forming pile loops of different pile heights. Tensioning the pile loop yarns of pile lops is known on principle and serves to ensure a strong and even seating of the pile loops in the base fabric. For permitting the tensioning function, the down sinker is provided with a beak that takes up again the pile loops of several courses formed earlier and tensions them slightly so that their anchoring in the base fabric will be improved and their pile height will be evened. The upper edge of the beak constitutes the plane for tensioning of the pile loops so that their height level must correspond to the pile height of the pile loops.
In the known down sinkers, only a single plane is provided at a given level for tensioning the pile loops. In the inventive down sinker, by contrast, at least two planes are provided for tensioning the pile loop yarn so that this down sinker can also be used in the production of a knit fabric with pile loops of different pile heights.
The present invention moreover relates to a circular knitting machine for the production of plush-type knit fabric, which comprises the following elements:
(a) needles for forming stitches and pile loops, whose rising and lowering movement is controlled by a lifting cam lock along a needle cam;
(b) a down and knock-over sinker as well as a piling sinker, which are disposed in parallel with each other and whose reciprocating movement horizontal relative to the needles or the needle movement, respectively, is controlled by a sinker lock along a respective sinker cam for the down sinker or the piling sinker, respectively,
(c) control elements for needle selection in correspondence with the pattern, with a selected needle following the needle cam present at its location,
(d) yarn guiding means for feeding a base yarn as well as at least two loop or pile yarns.
The circular knitting machine is characterized by the provision that it comprises a piling sinker of the aforementioned kind. Due to its two planes for couliering a pile loop yarn, such a piling sinker permits the production of a plush-type knit fabric with different loop lengths (pile heights), with the possibility that the pile loops of different lengths may additionally be distinguished from each other by the material of the pile loop yarn (i.e. in terms of yarn quality, color, etc.).
The aforementioned circular knitting machine preferably comprises moreover a down sinker of the above-explained kind, which presents at least two planes for tensioning a pile loop yarn. With such a down sinker it is possible to ensure that the different pile loop systems of different pile heights will all be tensioned individually and that they are hence all fixedly anchored in the base fabric.
Eventually, the invention relates to a plush knit fabric with a base knit fabric formed by a base yarn and with pile loops projecting from the base knit fabric. The plush knit fabric is characterized by the provision that there are at least two groups of pile loops, with the pile loops of one group being distinguished by those of the other group(s) by their pile height and type of yarn. On account of the different pile heights of the pile loops, this plush knit fabric presents an esthetically attractive structure high/low appearance that is additionally enhanced by the fact that the pile loops of different heights are formed of different materials, which may encompass different colors, in particular.
The plush knit fabric is preferably processed by shearing off the higher pile loops so that two terminal yarns are created from each pile loop, which project from the base fabric. As in accordance with the present invention only the higher pile loops are clipped the lower pile loops are left as loops, without being cut open, thus forming a so-called xc3xa9pinglxc3xa9e material. As a whole, the plush knit fabric hence constitutes a mixture of velour and xc3xa9pinglxc3xa9e in its structure, with the two base yarn system materials being possibly distinguished from each other by their kind and by their color in particular.